Uploading to the workshop
Uploading items to the workshop is simple, you just need to know where the tool is to do so.
Currently, it is only possible to upload items to the workshop on Windows. In your game folder, find the
HeroesWorkshop.exe file and run it. Your game folder should be in your Steam folder. Typically, this is something like:
C:\Program Files (x86)\Steam\steamapps\common\Heroes of Hammerwatch\
To create a new item, simply fill in the information in the "New item" tab and hit Upload. To update an item already uploaded to the workshop, use the "Update item" tab.
For the thumbnail, you should put an image at least 200x200 in size.